The research team, funded through the NSW Health Prevention Research Support Program with additional support from the National Drug and Alcohol Research Centre and international funders including the National Institute on Drug Abuse and Australia’s National Health and Medical Research Council, set out with a deceptively simple question. What do comprehensive community initiatives achieve against tobacco use and tobacco-related harms, what approaches do they use, and what factors strengthen their impact? To answer it, they registered their protocol prospectively and searched five major bibliographic databases—Embase, Medline, CINAHL, PsycINFO, and the Cochrane Database of Systematic Reviews—alongside hand-searching the reference lists of every included article. The scale of the screening effort alone is striking: from 15,117 articles initially identified, only 40 studies survived the systematic winnowing process that defines modern evidence synthesis under the PRISMA 2020 reporting framework.

Those 40 studies covered a broader canvas than smoking alone. Thirty-nine of them assessed smoking behavior, five examined smokeless tobacco, five measured second-hand smoke exposure, and two looked at tobacco-related harms to health. The heterogeneity of outcomes meant that only a subset of studies could be pooled statistically. In the end, the meta-analysis incorporated 25 outcome estimates drawn from 17 studies that compared communities receiving a comprehensive initiative against those receiving no intervention or only a minimal one. Three tobacco outcomes lent themselves to quantitative pooling: any smoking in the past month, any at least weekly smoking, and any lifetime use of tobacco.

The headline numbers are worth examining closely, because they carry both promise and caution. For any smoking in the past month—the measure of recent smoking—the pooled analysis across 12 studies involving 161,245 participants yielded a relative risk of 0.88, with a 95 percent confidence interval of 0.82 to 0.94. In plain terms, people living in communities with comprehensive initiatives were about 12 percent less likely to have smoked recently than those in comparison communities, and because the confidence interval excludes 1.0, that finding is statistically significant. For at least weekly smoking, based on four studies and 4,569 participants, the relative risk was 0.69 (95 percent CI 0.46 to 1.03)—a substantial apparent reduction of nearly a third, but one that just crosses the threshold of conventional statistical significance. For lifetime use, pooled across six studies and 9,677 participants, the relative risk of 0.92 (95 percent CI 0.84 to 1.00) sat precisely at the boundary, suggesting a possible but unconfirmed protective effect on whether people ever take up smoking at all.

Crucially, the authors did not shy away from the weaknesses in their evidence base. The pooled estimates for recent smoking, while significant, emerged in the context of substantial statistical heterogeneity, with I-squared values ranging from 62.0 to 78.4 percent and tau-squared values between 0.0064 and 0.1115. In the language of meta-analysis, that means the individual studies varied considerably in their observed effects—more than would be expected by chance alone—raising questions about what distinguishes successful initiatives from less successful ones. Compounding the problem, the evaluations that fed into the pooled estimates were judged to be of low methodological quality, and, perhaps most tellingly, they were conducted more than ten years ago. Data were simply insufficient to support meta-analysis of additional outcomes, including smoking frequency, smokeless tobacco use, second-hand smoke exposure, or tobacco-related health harms, leaving those domains to qualitative synthesis alone.

That combination of significant pooled effects, high heterogeneity, and dated, low-quality evaluations explains the authors’ deliberately tentative conclusions. All of the effect estimates pointed in a positive direction—comprehensive community initiatives never appeared to make tobacco use worse—but the certainty around the magnitude of benefit is limited. What the review does establish with more confidence is a pattern in who benefits most: CCIs were most effective at reducing the proportion of people who already smoke, rather than preventing smoking from ever starting. This is an important reframing for a field that has often justified community-wide programs primarily as prevention investments aimed at young people. The evidence here suggests the strongest returns come from helping current smokers quit or cut back, a finding with direct implications for how communities should target their resources.

The moderators of impact—the characteristics that separate stronger initiatives from weaker ones—offer perhaps the most actionable insights in the entire review. Through subgroup and narrative analysis, the researchers found support for a specific combination of components: policies relating to cigarette price, supported by media campaigns, alongside school-based activities and parenting-related programs. This constellation makes intuitive sense from a behavioral science perspective. Price policies operate on the economic levers that decades of tobacco control research have identified as among the most powerful drivers of consumption, particularly for price-sensitive smokers. Media campaigns amplify and legitimize those policies, shaping social norms around smoking. School-based and parenting activities extend the intervention into the developmental settings where smoking behaviors are first formed. The implication is that comprehensiveness is not merely a matter of doing many things at once, but of doing the right things together, in a coordinated fashion.

The review also examined moderators including community type, level of engagement, the combination of initiative components, duration, recency, evaluation quality, and length of follow-up—factors that are rarely considered systematically in this literature. The fact that the authors explicitly modeled these variables marks a methodological advance over earlier reviews of community-based prevention, which have often treated CCIs as a monolithic category. It also exposes a structural problem in the field: if the best evidence available dates from more than a decade ago and relies on low-quality evaluation designs, then the contemporary enthusiasm for whole-of-community approaches to tobacco control is running ahead of its evidentiary foundations. Modern tobacco landscapes—dominated by vaping products, novel nicotine delivery systems, and evolving retail environments—may respond differently to community mobilization than the cigarette markets of the early 2000s did.

For policymakers and public health practitioners, the practical takeaways are nonetheless clear enough to act on, provided they are paired with honest expectations. Comprehensive community initiatives appear to deliver a modest but real reduction in recent smoking—roughly one in eight recent smokers avoided relative to comparison communities—when they incorporate price-related policies, media advocacy, school programs, and parenting support. They are best understood as tools for reducing active smoking rather than as inoculation against initiation. And the field urgently needs better evaluations: randomized or rigorously controlled designs, longer follow-up periods, measurement of smokeless tobacco and second-hand smoke outcomes, and contemporary studies that reflect today’s nicotine products. Gates and his team have done the laborious work of establishing where the evidence stands. The next chapter belongs to communities and researchers willing to test these coordinated models with the methodological rigor that a burden of this magnitude demands.

Subject of Research: Effectiveness of comprehensive community initiatives on tobacco use and related harms

Article Title: A systematic review and meta-analysis of comprehensive community initiatives on tobacco use and related harms

Article References: A systematic review and meta-analysis of comprehensive community initiatives on tobacco use and related harms. (n.d.). https://doi.org/10.1186/s12889-026-29713-y

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29713-y

Keywords: tobacco control, smoking cessation, comprehensive community initiatives, systematic review, meta-analysis, public health, smokeless tobacco, second-hand smoke, smoking prevention, health policy, community health, evidence synthesis

The scale of exposure is striking. Researchers estimate that 241 million people aged 15 years and older were chewing tobacco users in 2023, a global prevalence of 3.9 percent, with use more than twice as common among males as among females. Despite decades of progress in tobacco control that has driven down smoking rates in many parts of the world, the global prevalence of chewing tobacco use has remained essentially unchanged. No country recorded a significant decrease in the number of users between 1990 and 2023, while 24 countries saw significant increases in the size of their chewing tobacco populations. That stagnation stands in sharp contrast to the trajectory of smoked tobacco and suggests that chewing products have largely escaped the taxation, advertising bans, and public awareness campaigns that have reshaped cigarette consumption.

Geographically, the burden maps onto a narrow band of the planet. South Asia had the highest regional concentration of use, with 14.6 percent of people aged 15 and older using chewing tobacco in 2023, and the region accounted for an estimated 210,000 chewing tobacco-related deaths, about 84 percent of the global total. At the country level, age-standardized prevalence reached 24.4 percent in Palau, followed by Bangladesh at 23.4 percent and Nepal at 17.5 percent. More than 90 percent of male chewing tobacco-related deaths and disability occurred in just ten countries: India, Bangladesh, China, Pakistan, Myanmar, the United States, Nepal, Sri Lanka, the Philippines, and Madagascar. Among females, more than 90 percent of the burden was concentrated in India, Bangladesh, Pakistan, Indonesia, Myanmar, China, Thailand, Cambodia, Vietnam, and Nepal. The researchers caution that these figures reflect absolute numbers of deaths and disability, so countries with larger populations can account for a greater share of the burden even when their per-capita rates are not the highest.

“Chewing tobacco is not a uniform public health problem, and our findings show that a relatively small number of countries bear an overwhelming share of its health burden,” said Gabriela Gil, lead author and Research Scientist at IHME. “Understanding how patterns of use differ within these populations is critical to designing more effective prevention and tobacco control strategies.” Her point underscores a methodological strength of the new analysis: by disaggregating chewing tobacco from other smokeless products and estimating exposure country by country, the study gives policymakers a far more granular picture of where interventions are likely to yield the greatest returns.

The demographic architecture of chewing tobacco use differs sharply by age and sex, and those differences vary by setting in ways that complicate prevention. Globally, use was more common among males, rising through early adulthood and continuing to climb with age before peaking among people aged 60 to 64. In South Asia, nearly one in five males and one in ten females used chewing tobacco in 2023. Male use in the region peaked at ages 60 to 64, while female use peaked among adults aged 80 and older, a pattern consistent with long-duration, lifelong habits established decades earlier. Bangladesh, however, reverses the broader trend: chewing tobacco use was higher among females than males across all age groups older than 30, even though the products remained common among both sexes. “These findings show why chewing tobacco control cannot take a one-size-fits-all approach,” said Dr. Emmanuela Gakidou, senior author and Professor in the Department of Health Metrics Sciences at IHME. “Prevention and cessation strategies need to reflect how patterns of use differ by country, age, and sex, as well as the cultural and social factors that shape tobacco use in each setting.”

On the health outcomes side, the study employed the Burden of Proof framework, a systematic approach for quantifying the risks associated with a given exposure, to estimate the burden attributable to chewing tobacco across six outcomes: stroke, lip and oral cavity cancer, esophageal cancer, other pharyngeal cancer, laryngeal cancer, and nasopharyngeal cancer. The results challenge the common perception that chewing tobacco is primarily an oral cancer risk. Stroke accounted for the largest share of chewing tobacco-related health loss globally, at 55.9 disability-adjusted life-years, or DALYs, per 100,000 people, followed by lip and oral cavity cancer at 17.4 per 100,000. DALYs are a composite metric that combines years of life lost to premature death with years lived in disability, providing a single measure of total health loss. The prominence of stroke indicates that the cardiovascular consequences of chewing tobacco, likely driven by nicotine absorption and its effects on blood pressure and vascular function, may be as consequential as, or more consequential than, the cancers that dominate public perception of the habit.

The cancer burden remains substantial nonetheless. Chewing tobacco was responsible for 17.3 percent of lip and oral cavity cancer DALYs worldwide, a figure that rose to 30.5 percent in South Asia, where products such as betel quid with tobacco are deeply embedded in social and cultural practice. The concentration of oral cancer risk in the same region that dominates overall chewing tobacco mortality creates a compounding public health challenge: health systems in Bangladesh, India, Nepal, and neighboring countries face elevated rates of both cardiovascular disease and head and neck cancers attributable to a single exposure, straining diagnostic, surgical, and oncology services that are often already under-resourced.

The trajectory of the burden is also alarming. The number of DALYs attributed to chewing tobacco increased by 116 percent between 1990 and 2023, reaching 6.48 million globally. Most of that burden came from premature death, accounting for 6.17 million years of life lost in 2023, a signal that chewing tobacco is killing users early rather than merely adding years of chronic illness. Population growth and aging in high-prevalence countries help explain part of the increase, since even stable prevalence rates translate into more users and more deaths as populations expand, but the finding that no country achieved a significant decline in user numbers means the growth in burden has been met with essentially no counteracting progress in exposure reduction.

Why has chewing tobacco escaped the attention devoted to cigarettes? The study points to a convergence of factors: longstanding cultural and social practices that normalize the habit, widespread misconceptions that chewing products are less harmful than smoking, limited surveillance systems that fail to track smokeless tobacco use separately, and higher rates of use among rural and lower-income populations who may have less access to cessation services and health information. These dynamics have left a gap in global tobacco control, in which smokeless products are frequently absent from taxation schemes, graphic warning requirements, and cessation programs designed around cigarettes.

The authors argue that reducing chewing tobacco-related deaths and disability will require stronger integration of smokeless tobacco prevention and cessation into national tobacco control and noncommunicable disease strategies, with approaches tailored to differences by age, sex, local patterns of use, and socioeconomic context. Given that more than 90 percent of the burden clusters in ten countries for each sex, even modest, well-targeted interventions in those settings could avert a disproportionate share of the global toll. As the GBD 2023 analysis makes clear, the world’s progress against tobacco will remain incomplete until the products tucked in the cheeks of 241 million users receive the same scrutiny as the cigarette.

Subject of Research: The global, regional, and national burden of chewing tobacco use and its attributable deaths and disability from 1990 to 2023

Article Title: Chewing tobacco linked to 251,000 deaths worldwide, with more than 90% of health loss concentrated in 10 countries

Article References: Chewing tobacco linked to 251,000 deaths worldwide, with more than 90% of health loss concentrated in 10 countries. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: chewing tobacco, Global Burden of Disease, smokeless tobacco, stroke, oral cavity cancer, South Asia, DALYs, tobacco control, IHME, public health, prevalence, The Lancet Global Health